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From:   Francesco Ruggeri <fruggeri@arista.com>
Date:   Thu, 17 Sep 2020 17:40:06 -0700
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Subject: Re: [PATCH v3] net: use exponential backoff in netdev_wait_allrefs
To:     Stephen Hemminger <stephen@networkplumber.org>
Cc:     open list <linux-kernel@vger.kernel.org>,
        netdev <netdev@vger.kernel.org>,
        Cong Wang <xiyou.wangcong@gmail.com>,
        Taehee Yoo <ap420073@gmail.com>,
        Andrii Nakryiko <andriin@fb.com>,
        Eric Dumazet <edumazet@google.com>,
        Jiri Pirko <jiri@mellanox.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>,
        David Miller <davem@davemloft.net>
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On Thu, Sep 17, 2020 at 5:02 PM Stephen Hemminger
<stephen@networkplumber.org> wrote:
> Is there anyway to make RCU trigger faster?

This is a case of the networking code requiring multiple cascading grace periods
(functions executing at the end of a period scheduling more functions
for the end
of the next period), so it's a matter of how many steps are required,
rather than
how fast each step is, if that is what you are suggesting. I don't
think that expediting
rcu periods would help in this case, but I will defer to people with better
knowledge of the networking code than me to comment.